1. Field of the Invention
This invention relates to cycloaliphatic epoxides and an epoxidation process using hydrogen peroxide as oxidizing agent.
2. Description of the Prior Art
Recently, a variety of unsaturated polymers have been epoxidized with hydrogen peroxide in the presence of a quaternary ammonium tetrakis (diperoxotungsto) phosphate catalyst, (J. Poly. Sci. Part C: Poly. Lett. 1990, 28, 285; J. Poly Sci.: Part A; Poly Chem. 1991, 29, 547). This process suffers from certain disadvantages, e.g., the catalyst is not readily available.
Cyclic epoxides are very reactive towards ring opening reactions due to the high ring strain associated with the ring structure, and thus they are very difficult to prepare. Cyclic epoxide precursors are very sensitive to reaction conditions. Currently, these precursors are epoxidized using peracids with careful pH control. Organic acids are used and generated during the epoxidation process.
Cyclic olefins have been epoxidized under phase transfer conditions. However, unsaturated cyclic substrates containing ester or ether linkages are sensitive to side reactions such as cleavage. Epoxidation of these types of substrates under phase transfer conditions has not been demonstrated in the prior art.
U.S. Pat Nos. 3,360,501; 3,023,174; and 2,988,554; and UK specification 907,149, assigned to Ciba Ltd.; and U.S. Pat. Nos. 2,917,491; 2,890,209; 2,863,881; 2,853,499; 2,853,498; 2,745,847; and 2,750,395 assigned to Union Carbide Corporation teach processes which can produce cyclic epoxides having up to two cycloaliphatic rings. U.S. Pat. No. 3,671,592 assigned to Nitto Electric Industrial Co.; and U.S. Pat. No. 3,558,665 assigned to Argus Chemical Co., and Japanese Kokai 39-2473 of Mar. 10, 1964 assigned to Kanegafuchi Spinning Co., Ltd., also teach processes which can produce cyclic epoxides having only up to two cycloaliphatic rings.
Processes for producing cyclic epoxides having three or more cycloaliphatic rings have not been provided or suggested by the prior art.